Autolykos 2 validation for custom message

core/shared/src/main/scala/sigma/SigmaDsl.scala

@@ -490,7 +490,6 @@ trait Header {
     * @return result of header's proof-of-work validation
     */
   def checkPow: Boolean
-
 }
 
 /** Runtime representation of Context ErgoTree type.
@@ -790,6 +789,12 @@ trait SigmaDslBuilder {
   /** Returns a byte-wise XOR of the two collections of bytes. */
   def xor(l: Coll[Byte], r: Coll[Byte]): Coll[Byte]
 
+  /** Calculates value of a custom Autolykos 2 hash function */
+  def powHit(k: Int, msg: Coll[Byte], nonce: Coll[Byte], h: Coll[Byte], N: Int): BigInt
+
+  /** Deserializes provided `bytes` into a value of type `T`. **/
+  def deserializeTo[T](bytes: Coll[Byte])(implicit cT: RType[T]): T
+
   /** Returns a number decoded from provided big-endian bytes array. */
   def fromBigEndianBytes[T](bytes: Coll[Byte])(implicit cT: RType[T]): T
 }

core/shared/src/main/scala/sigma/reflection/ReflectionData.scala

@@ -469,9 +469,16 @@ object ReflectionData {
         mkMethod(clazz, "decodePoint", Array[Class[_]](cColl)) { (obj, args) =>
           obj.asInstanceOf[SigmaDslBuilder].decodePoint(args(0).asInstanceOf[Coll[Byte]])
         },
+        mkMethod(clazz, "deserializeTo", Array[Class[_]](cColl, classOf[RType[_]])) { (obj, args) =>
+          obj.asInstanceOf[SigmaDslBuilder].deserializeTo(args(0).asInstanceOf[Coll[Byte]])(args(1).asInstanceOf[RType[_]])
+        },
         mkMethod(clazz, "fromBigEndianBytes", Array[Class[_]](cColl, classOf[RType[_]])) { (obj, args) =>
           obj.asInstanceOf[SigmaDslBuilder].fromBigEndianBytes(args(0).asInstanceOf[Coll[Byte]])(args(1).asInstanceOf[RType[_]])
         },
+        mkMethod(clazz, "powHit", Array[Class[_]](classOf[Int], cColl, cColl, cColl, classOf[Int])) { (obj, args) =>
+          obj.asInstanceOf[SigmaDslBuilder].powHit(args(0).asInstanceOf[Int], args(1).asInstanceOf[Coll[Byte]],
+            args(2).asInstanceOf[Coll[Byte]], args(3).asInstanceOf[Coll[Byte]], args(4).asInstanceOf[Int])
+        },
         mkMethod(clazz, "encodeNbits", Array[Class[_]](classOf[BigInt])) { (obj, args) =>
           obj.asInstanceOf[SigmaDslBuilder].encodeNbits(args(0).asInstanceOf[BigInt])
         },

core/shared/src/main/scala/sigma/serialization/CoreDataSerializer.scala

@@ -135,7 +135,7 @@ class CoreDataSerializer {
     res
   }
 
-  def deserializeColl[T <: SType](len: Int, tpeElem: T, r: CoreByteReader): Coll[T#WrappedType] =
+  private def deserializeColl[T <: SType](len: Int, tpeElem: T, r: CoreByteReader): Coll[T#WrappedType] =
     tpeElem match {
       case SBoolean =>
         Colls.fromArray(r.getBits(len)).asInstanceOf[Coll[T#WrappedType]]

data/shared/src/main/scala/sigma/SigmaDataReflection.scala

@@ -359,6 +359,21 @@ object SigmaDataReflection {
           obj.asInstanceOf[SGlobalMethods.type].serialize_eval(args(0).asInstanceOf[MethodCall],
             args(1).asInstanceOf[SigmaDslBuilder],
             args(2).asInstanceOf[SType#WrappedType])(args(3).asInstanceOf[ErgoTreeEvaluator])
+        },
+        mkMethod(clazz, "deserializeTo_eval", Array[Class[_]](classOf[MethodCall], classOf[SigmaDslBuilder], classOf[Coll[_]], classOf[ErgoTreeEvaluator])) { (obj, args) =>
+          obj.asInstanceOf[SGlobalMethods.type].deserializeTo_eval(args(0).asInstanceOf[MethodCall],
+            args(1).asInstanceOf[SigmaDslBuilder],
+            args(2).asInstanceOf[Coll[Byte]])(args(3).asInstanceOf[ErgoTreeEvaluator])
+        },
+        mkMethod(clazz, "powHit_eval", Array[Class[_]](classOf[MethodCall], classOf[SigmaDslBuilder], classOf[Int], classOf[Coll[_]], classOf[Coll[_]], classOf[Coll[_]], classOf[Int], classOf[ErgoTreeEvaluator])) { (obj, args) =>
+          obj.asInstanceOf[SGlobalMethods.type].powHit_eval(args(0).asInstanceOf[MethodCall],
+            args(1).asInstanceOf[SigmaDslBuilder],
+            args(2).asInstanceOf[Int],
+            args(3).asInstanceOf[Coll[Byte]],
+            args(4).asInstanceOf[Coll[Byte]],
+            args(5).asInstanceOf[Coll[Byte]],
+            args(6).asInstanceOf[Int]
+          )(args(7).asInstanceOf[ErgoTreeEvaluator])
         }
       )
     )

data/shared/src/main/scala/sigma/ast/CostKind.scala

@@ -1,5 +1,7 @@
 package sigma.ast
 
+import sigma.Coll
+
 import scala.runtime.Statics
 
 /** Cost descriptor of a single operation, usually associated with
@@ -52,5 +54,37 @@ abstract class TypeBasedCost extends CostKind {
   * See [[EQ]], [[NEQ]]. */
 case object DynamicCost extends CostKind
 
+/**
+  * Cost of  converting numeric value to the numeric value of the given type, i.e. Byte -> Int
+  */
+object NumericCastCostKind extends TypeBasedCost {
+  override def costFunc(targetTpe: SType): JitCost = targetTpe match {
+    case SBigInt => JitCost(30)
+    case _ => JitCost(10)
+  }
+}
+
+/**
+  * Cost of Global.powHit method, which is dependent on few parameters, see cost() function description
+  */
+object PowHitCostKind extends CostKind {
+  /**
+    * @param k - k parameter of Autolykos 2 (number of inputs in k-sum problem)"
+    * @param msg - message to calculate Autolykos hash 2 for
+    * @param nonce - used to pad the message to get Proof-of-Work hash function output with desirable properties
+    * @param h - PoW protocol specific padding for table uniqueness (e.g. block height in Ergo)
+    * @return cost of custom Autolykos2 hash function invocation
+    */
+  def cost(k: Int, msg: Coll[Byte], nonce: Coll[Byte], h: Coll[Byte]): JitCost = {
+    val chunkSize = CalcBlake2b256.costKind.chunkSize
+    val perChunkCost = CalcBlake2b256.costKind.perChunkCost
+    val baseCost = 300
+
+    // the heaviest part inside is k + 1 Blake2b256 invocations
+    val c = baseCost + (k + 1) * ((msg.length + nonce.length + h.length) / chunkSize + 1) * perChunkCost.value
+    JitCost(c)
+  }
+}
+
 
 

data/shared/src/main/scala/sigma/ast/SMethod.scala

@@ -155,8 +155,7 @@ case class SMethod(
     val methodName = name + "_eval"
     val m = try {
       objType.thisRClass.getMethod(methodName, paramTypes:_*)
-    }
-    catch { case e: NoSuchMethodException =>
+    } catch { case e: NoSuchMethodException =>
       throw new RuntimeException(s"Cannot find eval method def $methodName(${Seq(paramTypes:_*)})", e)
     }
     m
@@ -339,7 +338,7 @@ object SMethod {
     * @return an instance of [[SMethod]] which may contain generic type variables in the
     *         signature (see SMethod.stype). As a result `specializeFor` is called by
     *         deserializer to obtain monomorphic method descriptor.
-    * @consensus this is method is used in [[sigmastate.serialization.MethodCallSerializer]]
+    * @consensus this is method is used in [[sigma.serialization.MethodCallSerializer]]
     *            `parse` method and hence it is part of consensus protocol
     */
   def fromIds(typeId: Byte, methodId: Byte): SMethod = {

data/shared/src/main/scala/sigma/ast/SigmaPredef.scala

@@ -432,6 +432,25 @@ object SigmaPredef {
       )
     )
 
+    val DeserializeToFunc = PredefinedFunc("deserializeTo",
+      Lambda(Seq(paramT), Array("bytes" -> SByteArray), tT, None),
+      irInfo = PredefFuncInfo(
+        irBuilder = { case (u, args) =>
+          val resType = u.opType.tRange.asInstanceOf[SFunc].tRange
+          MethodCall(
+            Global,
+            SGlobalMethods.deserializeToMethod.withConcreteTypes(Map(tT -> resType)),
+            args.toIndexedSeq,
+            Map(tT -> resType)
+          )
+        }),
+      docInfo = OperationInfo(MethodCall,
+        """Deserializes provided bytes into a value of given type using the default serialization format.
+        """.stripMargin,
+        Seq(ArgInfo("bytes", "bytes to deserialize"))
+      )
+    )
+
     val FromBigEndianBytesFunc = PredefinedFunc("fromBigEndianBytes",
       Lambda(Seq(paramT), Array("bytes" -> SByteArray), tT, None),
       irInfo = PredefFuncInfo(
@@ -480,6 +499,7 @@ object SigmaPredef {
       ExecuteFromVarFunc,
       ExecuteFromSelfRegFunc,
       SerializeFunc,
+      DeserializeToFunc,
       GetVarFromInputFunc,
       FromBigEndianBytesFunc
     ).map(f => f.name -> f).toMap

data/shared/src/main/scala/sigma/ast/methods.scala

@@ -2,6 +2,7 @@ package sigma.ast
 
 import org.ergoplatform._
 import org.ergoplatform.validation._
+import sigma.{Coll, VersionContext, _}
 import sigma.Evaluation.stypeToRType
 import sigma._
 import sigma.{VersionContext, _}
@@ -15,6 +16,7 @@ import sigma.data.NumericOps.BigIntIsExactIntegral
 import sigma.data.OverloadHack.Overloaded1
 import sigma.data.{CBigInt, DataValueComparer, KeyValueColl, Nullable, RType, SigmaConstants}
 import sigma.eval.{CostDetails, ErgoTreeEvaluator, TracedCost}
+import sigma.pow.Autolykos2PowValidation
 import sigma.reflection.RClass
 import sigma.serialization.CoreByteWriter.ArgInfo
 import sigma.serialization.{DataSerializer, SigmaByteWriter, SigmaSerializer}
@@ -1754,6 +1756,7 @@ case object SHeaderMethods extends MonoTypeMethods {
   lazy val powDistanceMethod      = propertyCall("powDistance", SBigInt, 14, FixedCost(JitCost(10)))
   lazy val votesMethod            = propertyCall("votes", SByteArray, 15, FixedCost(JitCost(10)))
 
+  // methods added in 6.0 below
   // cost of checkPoW is 700 as about 2*32 hashes required, and 1 hash (id) over short data costs 10
   lazy val checkPowMethod = SMethod(
     this, "checkPow", SFunc(Array(SHeader), SBoolean), 16, FixedCost(JitCost(700)))
@@ -1824,6 +1827,35 @@ case object SGlobalMethods extends MonoTypeMethods {
     .withInfo(Xor, "Byte-wise XOR of two collections of bytes",
       ArgInfo("left", "left operand"), ArgInfo("right", "right operand"))
 
+  lazy val powHitMethod = SMethod(
+    this, "powHit", SFunc(Array(SGlobal, SInt, SByteArray, SByteArray, SByteArray, SInt), SBigInt), methodId = 8,
+    PowHitCostKind)
+    .withIRInfo(MethodCallIrBuilder)
+    .withInfo(MethodCall,
+      "Calculating Proof-of-Work hit (Autolykos 2 hash value) for custom Autolykos 2 function",
+      ArgInfo("k", "k parameter of Autolykos 2 (number of inputs in k-sum problem)"),
+      ArgInfo("msg", "Message to calculate Autolykos hash 2 for"),
+      ArgInfo("nonce", "Nonce used to pad the message to get Proof-of-Work hash function output with desirable properties"),
+      ArgInfo("h", "PoW protocol specific padding for table uniqueness (e.g. block height in Ergo)"),
+      ArgInfo("N", "Size of table filled with pseudo-random data to find k elements in")
+    )
+
+  def powHit_eval(mc: MethodCall, G: SigmaDslBuilder, k: Int, msg: Coll[Byte], nonce: Coll[Byte], h: Coll[Byte], N: Int)
+                 (implicit E: ErgoTreeEvaluator): BigInt = {
+    val cost = PowHitCostKind.cost(k, msg, nonce, h)
+    E.addCost(FixedCost(cost), powHitMethod.opDesc)
+    CBigInt(Autolykos2PowValidation.hitForVersion2ForMessageWithChecks(k, msg.toArray, nonce.toArray, h.toArray, N).bigInteger)
+  }
+
+  private val deserializeCostKind = PerItemCost(baseCost = JitCost(30), perChunkCost = JitCost(20), chunkSize = 32)
+
+  lazy val deserializeToMethod = SMethod(
+    this, "deserializeTo", SFunc(Array(SGlobal, SByteArray), tT, Array(paramT)), 4, deserializeCostKind, Seq(tT))
+    .withIRInfo(MethodCallIrBuilder,
+      javaMethodOf[SigmaDslBuilder, Coll[Byte], RType[_]]("deserializeTo"))
+    .withInfo(MethodCall, "Deserialize provided bytes into an object of requested type",
+      ArgInfo("first", "Bytes to deserialize"))
+
   /** Implements evaluation of Global.xor method call ErgoTree node.
     * Called via reflection based on naming convention.
     * @see SMethod.evalMethod, Xor.eval, Xor.xorWithCosting
@@ -1859,6 +1891,15 @@ case object SGlobalMethods extends MonoTypeMethods {
     .withIRInfo(MethodCallIrBuilder)
     .withInfo(MethodCall, "Decode nbits-encoded big integer number", ArgInfo("nbits", "NBits-encoded argument"))
 
+  def deserializeTo_eval(mc: MethodCall, G: SigmaDslBuilder, bytes: Coll[Byte])
+                        (implicit E: ErgoTreeEvaluator): Any = {
+    val tpe = mc.tpe
+    val cT = stypeToRType(tpe)
+    E.addSeqCost(deserializeCostKind, bytes.length, deserializeToMethod.opDesc) { () =>
+      G.deserializeTo(bytes)(cT)
+    }
+  }
+
   lazy val serializeMethod = SMethod(this, "serialize",
     SFunc(Array(SGlobal, tT), SByteArray, Array(paramT)), 3, DynamicCost)
       .withIRInfo(MethodCallIrBuilder)
@@ -1894,6 +1935,8 @@ case object SGlobalMethods extends MonoTypeMethods {
         groupGeneratorMethod,
         xorMethod,
         serializeMethod,
+        powHitMethod,
+        deserializeToMethod,
         encodeNBitsMethod,
         decodeNBitsMethod,
         fromBigEndianBytesMethod

data/shared/src/main/scala/sigma/ast/trees.scala

@@ -414,18 +414,6 @@ trait NumericCastCompanion extends ValueCompanion {
   def costKind: TypeBasedCost = NumericCastCostKind
 }
 
-/** Cost of:
-  * 1) converting numeric value to the numeric value of the given type, i.e. Byte -> Int
-  * NOTE: the cost of BigInt casting is the same in JITC (comparing to AOTC) to simplify
-  * implementation.
-  */
-object NumericCastCostKind extends TypeBasedCost {
-  override def costFunc(targetTpe: SType): JitCost = targetTpe match {
-    case SBigInt => JitCost(30)
-    case _ => JitCost(10)
-  }
-}
-
 object Upcast extends NumericCastCompanion {
   override def opCode: OpCode = OpCodes.UpcastCode
   override def argInfos: Seq[ArgInfo] = UpcastInfo.argInfos

data/shared/src/main/scala/sigma/data/CHeader.scala

@@ -71,7 +71,11 @@ class CHeader(val ergoHeader: ErgoHeader) extends Header with WrapperOf[ErgoHead
   }
 
   override def checkPow: Boolean = {
-    Autolykos2PowValidation.checkPoWForVersion2(this)
+    if (version == 1) {
+      throw new Exception("Autolykos v1 is not supported") //todo: more specific exception?
+    } else {
+      Autolykos2PowValidation.checkPoWForVersion2(this)
+    }
   }
 
   override def toString: String =

data/shared/src/main/scala/sigma/data/CSigmaDslBuilder.scala

@@ -1,23 +1,28 @@
 package sigma.data
 
 import debox.cfor
-import org.ergoplatform.ErgoBox
+import org.ergoplatform.{ErgoBox, ErgoHeader}
 import org.ergoplatform.validation.ValidationRules
 import scorex.crypto.hash.{Blake2b256, Sha256}
+import scorex.util.serialization.VLQByteBufferReader
 import scorex.utils.{Ints, Longs}
 import sigma.ast.{AtLeast, SBigInt, SubstConstants}
 import scorex.utils.Longs
+import sigma.Evaluation.rtypeToSType
 import sigma.ast.{AtLeast, SType, SubstConstants}
 import sigma.crypto.{CryptoConstants, EcPointType, Ecp}
 import sigma.eval.Extensions.EvalCollOps
+import sigma.serialization.{ConstantStore, DataSerializer, GroupElementSerializer, SigmaByteReader, SigmaSerializer}
 import sigma.serialization.{DataSerializer, GroupElementSerializer, SigmaSerializer}
-import sigma.serialization.{GroupElementSerializer, SerializerException, SigmaSerializer}
+import sigma.serialization.SerializerException
+import sigma.pow.Autolykos2PowValidation
 import sigma.util.Extensions.BigIntegerOps
 import sigma.util.NBitsUtils
 import sigma.validation.SigmaValidationSettings
 import sigma.{AvlTree, BigInt, Box, Coll, CollBuilder, Evaluation, GroupElement, SigmaDslBuilder, SigmaProp, VersionContext}
 
 import java.math.BigInteger
+import java.nio.ByteBuffer
 
 /** A default implementation of [[SigmaDslBuilder]] interface.
   *
@@ -254,6 +259,19 @@ class CSigmaDslBuilder extends SigmaDslBuilder { dsl =>
     DataSerializer.serialize(value.asInstanceOf[SType#WrappedType], tpe, w)
     Colls.fromArray(w.toBytes)
   }
+
+  override def powHit(k: Int, msg: Coll[Byte], nonce: Coll[Byte], h: Coll[Byte], N: Int): BigInt = {
+    val bi = Autolykos2PowValidation.hitForVersion2ForMessageWithChecks(k, msg.toArray, nonce.toArray, h.toArray, N)
+    this.BigInt(bi.bigInteger)
+  }
+
+
+  def deserializeTo[T](bytes: Coll[Byte])(implicit cT: RType[T]): T = {
+    val tpe = rtypeToSType(cT)
+    val reader = new SigmaByteReader(new VLQByteBufferReader(ByteBuffer.wrap(bytes.toArray)), new ConstantStore(), false)
+    val res = DataSerializer.deserialize(tpe, reader)
+    res.asInstanceOf[T]
+  }
 }
 
 /** Default singleton instance of Global object, which implements global ErgoTree functions. */

data/shared/src/main/scala/sigma/pow/Autolykos2PowValidation.scala

@@ -112,8 +112,14 @@ object Autolykos2PowValidation {
     toBigInt(hash(Bytes.concat(indexBytes, heightBytes, M)).drop(1))
   }
 
-  def hitForVersion2ForMessage(k: Int, msg: Array[Byte], nonce: Array[Byte], h: Array[Byte], N: Int): BigInt = {
+  def hitForVersion2ForMessageWithChecks(k: Int, msg: Array[Byte], nonce: Array[Byte], h: Array[Byte], N: Int): BigInt = {
+    require(k >= 2) // at least 2 elements needed for sum
+    require(k <= 32) // genIndexes function of Autolykos2 not supporting k > 32
+    require(N >= 16) // min table size
+    hitForVersion2ForMessage(k, msg, nonce, h, N)
+  }
 
+  private def hitForVersion2ForMessage(k: Int, msg: Array[Byte], nonce: Array[Byte], h: Array[Byte], N: Int): BigInt = {
     val prei8 = BigIntegers.fromUnsignedByteArray(hash(Bytes.concat(msg, nonce)).takeRight(8))
     val i = BigIntegers.asUnsignedByteArray(4, prei8.mod(BigInt(N).underlying()))
     val f = Blake2b256(Bytes.concat(i, h, M)).drop(1) // .drop(1) is the same as takeRight(31)

docs/LangSpec.md

@@ -68,7 +68,7 @@ The following sections describe ErgoScript and its operations.
 #### Operations and constructs overview
 
 - Binary operations: `>, <, >=, <=, +, -, &&, ||, ==, !=, |, &, *, /, %, ^, ++`
-- predefined primitives: `serialize`, `blake2b256`, `byteArrayToBigInt`, `proveDlog` etc. 
+- predefined primitives: `deserializeTo`, `serialize`, `blake2b256`, `byteArrayToBigInt`, `proveDlog` etc. 
 - val declarations: `val h = blake2b256(pubkey)`
 - if-then-else clause: `if (x > 0) 1 else 0`
 - collection literals: `Coll(1, 2, 3, 4)`
@@ -903,6 +903,10 @@ def blake2b256(input: Coll[Byte]): Coll[Byte]
 /** Cryptographic hash function Sha256 (See scorex.crypto.hash.Sha256) */
 def sha256(input: Coll[Byte]): Coll[Byte]
 
+/** Create an instance of type T from bytes of its wrapped type. 
+See https://github.com/ScorexFoundation/sigmastate-interpreter/pull/979 for more details */
+def deserializeTo[T](input: Coll[Byte]): T
+
 /** Create BigInt from a collection of bytes. */
 def byteArrayToBigInt(input: Coll[Byte]): BigInt
 

interpreter/shared/src/main/scala/sigmastate/interpreter/Interpreter.scala

@@ -126,7 +126,7 @@ trait Interpreter {
     case _ => None
   }
 
-  /** Extracts proposition for ErgoTree handing soft-fork condition.
+  /** Extracts proposition for ErgoTree handling soft-fork condition.
     * @note soft-fork handler */
   protected def propositionFromErgoTree(ergoTree: ErgoTree, context: CTX): SigmaPropValue = {
     val validationSettings = context.validationSettings